how to clear a checked radio button?

I set created radio button with conditions. However once the button is checked, it seems cannot be unchecked. What setting can I use so once reload the page, the radio button is unchecked?

Thanks!

If you only have one option for the radio button field on your account just like on the image you have posted, I would suggest you use the checkbox field instead. 

By the way, I have checked your form and I can see that when it loaded the radio button for that option is not checked on load.

Should you have any other questions or concerns, please feel free to let us know and we will be glad to help you. Thank you.